import { nullable } from "https://deno.land/x/fun@v2.0.0/refinement.ts";
Turn a Refinement<A, B>
into Refinement<null | A, null | B>
.
Examples
Example 1
Example 1
import * as R from "./refinement.ts";
const nullOrNum = R.nullable(R.number);
const result1 = nullOrNum(null); // true, variable is now null | number
const result2 = nullOrNum(1); // true, variable is now null | number
const result3 = nullOrNum("hello"); // false
Type Parameters
B extends A
Parameters
or: Refinement<A, B>
Returns
Refinement<A | null, B | null>